In Islip, the damage is estimated at about $20 million so far, Xirinachs reported.

“It’s very important for us to be able to find a definite number so that we can provide that to FEMA, so that we can get reimbursement and so that we can provide some funds for some of these families,” said Councilwoman Trish Bergen.

The rainstorm that slammed Suffolk on Aug. 13 dropped 13.5 inches of rain in some areas, setting a new state record for the most amount of rainfall over a 24-hour period.

The FEMA investigators will be in Suffolk County all week focusing most of their time in Bayblon, Brookhaven and Islip.